Print trivia after short record type declaration. Fixes #774 (#775)

src/Fantomas.Tests/RecordTests.fs

@@ -882,4 +882,31 @@ let meh =
     { // this comment right
       Name = "FOO"
       Level = 78 }
+"""
+
+[<Test>]
+let ``line comment after short syntax record type, 774`` () =
+    formatSourceString false """type FormatConfig = {
+    PageWidth: int
+    Indent: int } // The number of spaces
+"""  config
+    |> should equal """type FormatConfig = { PageWidth: int; Indent: int } // The number of spaces
+"""
+
+[<Test>]
+let ``line comment after short record instance syntax`` () =
+    formatSourceString false """let formatConfig = {
+    PageWidth = 70
+    Indent = 8 } // The number of spaces
+"""  config
+    |> should equal """let formatConfig = { PageWidth = 70; Indent = 8 } // The number of spaces
+"""
+
+[<Test>]
+let ``line comment after short anonymous record instance syntax`` () =
+    formatSourceString false """let formatConfig = {|
+    PageWidth = 70
+    Indent = 8 |} // The number of spaces
+"""  config
+    |> should equal """let formatConfig = {| PageWidth = 70; Indent = 8 |} // The number of spaces
 """

src/Fantomas/CodePrinter.fs

@@ -1861,7 +1861,10 @@ and genTypeDefn astContext (TypeDef(ats, px, ao, tds, tcs, tdr, ms, s, preferPos
 
         let bodyExpr ctx =
             if (List.isEmpty ms) then
-                (isShortExpression ctx.Config.MaxRecordWidth shortExpression multilineExpression) ctx
+                (isShortExpression ctx.Config.MaxRecordWidth shortExpression multilineExpression
+                +> leaveNode tdr.Range // this will only print something when there is trivia after } in the short expression
+                // Yet it cannot be part of the short expression otherwise the multiline expression would be triggered unwillingly.
+                ) ctx
             else
                 multilineExpression ctx